Los Angeles Mayor Antonio Villaraigosa — prominent supporter of same-sex marriage and chairman of the 2012 Democratic National Convention — told CNN’s John King that he knew in advance (“a couple of weeks ago”) that President Obama was going to switch positions on the controversial social issue.

And, unlike the Vice President of the United States, he kept his mouth shut.

Biden’s blunder — he shot off his mouth on Sunday’s edition of Meet the Press — angered White House aides, provoked an abject apology from the Veep and forced the president to speed up the planned announcement.

Villaraigosa’s discretion — well, it didn’t make headlines.

But the California politician, a rising star in national Democratic politics, got to take a curtain call of sorts on CNN’s John King USA program last night.

“I did know a couple of weeks ago that something would be said soon on this issue,” he told King.

He said the Obama team didn’t push back when he continued to be a strong public advocate of same-sex marriage — despite the president’s public opposition.

“First of all, I got no resistance from the campaign,” Villaraigosa said. “They knew where I was. They were supportive of me, you know, saying where I’ve been for a very long time on this issue. There was no resistance from the campaign with respect to me.”

Unlike some Democrats, Villaraigosa said he opposed moving the convention from Charlotte because North Carolina voters on Tuesday approved a state constitutional amendment barring same-sex marriage and civil unions.

“Look, we’re already far down the way in terms of planning for this convention,” he said. “It’s going to be the most open and accessible. North Carolina is an important state. We’re going to work to win the hearts and minds and votes of the voters there.”

Villaraigosa, who has supported same-sex marriage publicly since 1994, predicted that his position will be included in the party’s 2012 plaform.

“Because his position on marriage equality has evolved, he’s taken the position of conscience,” the mayor said. “I think it was a courageous decision on his part, and one that I support 100 percent. I’m very proud of our president.”